firmware: Add support for Airoha EN7581 NPU firmware

Add support for Airoha EN7581 NPU firmware present in linux-firmware.
Support for it is fully upstream with the Ethernet part fully pushed and
the Wireless Offload currently in progress for various WiFi chip.

Link: https://github.com/openwrt/openwrt/pull/19816
Signed-off-by: Christian Marangi <[email protected]>

package/firmware/linux-firmware/airoha.mk

@@ -15,3 +15,14 @@ endif
 endef
 
 $(eval $(call BuildPackage,airoha-en8811h-firmware))
+
+Package/airoha-en7581-npu-firmware = $(call Package/firmware-default,Airoha EN7581 NPU firmware,,LICENSE.airoha)
+define Package/airoha-en7581-npu-firmware/install
+	$(INSTALL_DIR) $(1)/lib/firmware/airoha
+	$(CP) \
+		$(PKG_BUILD_DIR)/airoha/en7581_npu_data.bin \
+		$(PKG_BUILD_DIR)/airoha/en7581_npu_rv32.bin \
+		$(1)/lib/firmware/airoha
+endef
+
+$(eval $(call BuildPackage,airoha-en7581-npu-firmware))